Unless such things were local I used to delegate our attendance to a staff member. "Here, Fred, there's a do on down in Melbourne. I'd like you to attend (it'll be good experience for you). Knock up a report and get it to me within the week will you?" I'm afraid that banging around the country with all the bother of transport etc. has never appealed to me. Others seemed to love it. Maybe they saw it as some sort of status thing rather than a tedious chore. That's not a criticism of your winging your way around the world, rab, just a personal opinion of a bloke who could get out of attending the blasted things.
In my line of work, the main reason for these things is so that people remember you still exist. If I could do this without 19hr journeys and leaving my family for a week, I would. People sometimes say "you're being paid to do it so quit your moaning" but my view is that travel is a perk only if it's (a) to places you actually want to go and (b) with people you actually want to go with. Work trips rarely count. (That said I do have some good mates at work and sometimes I get to go to agreeable places like Amsterdam or Vienna with them. I tend to be less fastidious about keeping my receipts on such occasions.)